With the ever developing of technologies, consumers are expecting more and more from LCD devices. Based on the light source used in the LCD, LCD devices may be classified into transmissive LCDs, reflective LCDs and transflective LCDs, among which transmissive LCDs are currently the most widely used in the display devices. The transmissive LCD devices display images using a backlight source, which is quite power consuming, thus making the power consumption of the entire LCD device high. In view of the above, most manufacturers are concerned with the issue of reducing the power consumption of LCD devices.